## Table of Contents

- [function](#function)
  - [CLI Microlink API example](#cli-microlink-api-example)
  - [cURL Microlink API example](#curl-microlink-api-example)
  - [JavaScript Microlink API example](#javascript-microlink-api-example)
  - [Python Microlink API example](#python-microlink-api-example)
  - [Ruby Microlink API example](#ruby-microlink-api-example)
  - [PHP Microlink API example](#php-microlink-api-example)
  - [Golang Microlink API example](#golang-microlink-api-example)
  - [Page](#page)
  - [CLI Microlink API example](#cli-microlink-api-example-1)
  - [cURL Microlink API example](#curl-microlink-api-example-1)
  - [JavaScript Microlink API example](#javascript-microlink-api-example-1)
  - [Python Microlink API example](#python-microlink-api-example-1)
  - [Ruby Microlink API example](#ruby-microlink-api-example-1)
  - [PHP Microlink API example](#php-microlink-api-example-1)
  - [Golang Microlink API example](#golang-microlink-api-example-1)
  - [CLI Microlink API example](#cli-microlink-api-example-2)
  - [cURL Microlink API example](#curl-microlink-api-example-2)
  - [JavaScript Microlink API example](#javascript-microlink-api-example-2)
  - [Python Microlink API example](#python-microlink-api-example-2)
  - [Ruby Microlink API example](#ruby-microlink-api-example-2)
  - [PHP Microlink API example](#php-microlink-api-example-2)
  - [Golang Microlink API example](#golang-microlink-api-example-2)
  - [CLI Microlink API example](#cli-microlink-api-example-3)
  - [cURL Microlink API example](#curl-microlink-api-example-3)
  - [JavaScript Microlink API example](#javascript-microlink-api-example-3)
  - [Python Microlink API example](#python-microlink-api-example-3)
  - [Ruby Microlink API example](#ruby-microlink-api-example-3)
  - [PHP Microlink API example](#php-microlink-api-example-3)
  - [Golang Microlink API example](#golang-microlink-api-example-3)
  - [CLI Microlink API example](#cli-microlink-api-example-4)
  - [cURL Microlink API example](#curl-microlink-api-example-4)
  - [JavaScript Microlink API example](#javascript-microlink-api-example-4)
  - [Python Microlink API example](#python-microlink-api-example-4)
  - [Ruby Microlink API example](#ruby-microlink-api-example-4)
  - [PHP Microlink API example](#php-microlink-api-example-4)
  - [Golang Microlink API example](#golang-microlink-api-example-4)
  - [Response](#response)
  - [CLI Microlink API example](#cli-microlink-api-example-5)
  - [cURL Microlink API example](#curl-microlink-api-example-5)
  - [JavaScript Microlink API example](#javascript-microlink-api-example-5)
  - [Python Microlink API example](#python-microlink-api-example-5)
  - [Ruby Microlink API example](#ruby-microlink-api-example-5)
  - [PHP Microlink API example](#php-microlink-api-example-5)
  - [Golang Microlink API example](#golang-microlink-api-example-5)
  - [Headers](#headers)
  - [CLI Microlink API example](#cli-microlink-api-example-6)
  - [cURL Microlink API example](#curl-microlink-api-example-6)
  - [JavaScript Microlink API example](#javascript-microlink-api-example-6)
  - [Python Microlink API example](#python-microlink-api-example-6)
  - [Ruby Microlink API example](#ruby-microlink-api-example-6)
  - [PHP Microlink API example](#php-microlink-api-example-6)
  - [Golang Microlink API example](#golang-microlink-api-example-6)
  - [Custom parameters](#custom-parameters)
  - [CLI Microlink API example](#cli-microlink-api-example-7)
  - [cURL Microlink API example](#curl-microlink-api-example-7)
  - [JavaScript Microlink API example](#javascript-microlink-api-example-7)
  - [Python Microlink API example](#python-microlink-api-example-7)
  - [Ruby Microlink API example](#ruby-microlink-api-example-7)
  - [PHP Microlink API example](#php-microlink-api-example-7)
  - [Golang Microlink API example](#golang-microlink-api-example-7)
- [Response](#response-1)
- [Plan limits](#plan-limits)
- [Compression](#compression)
- [NPM packages](#npm-packages)
- [Function constructor](#function-constructor)

---

[API](https://microlink.io/docs/api/getting-started/overview)

[GUIDES](https://microlink.io/docs/guides) [MQL](https://microlink.io/docs/mql/getting-started/overview) [SDK](https://microlink.io/docs/sdk/getting-started/overview) [CARDS](https://microlink.io/docs/cards/getting-started/overview)

API GUIDES MQL SDK CARDS

Getting Started

[Overview](https://microlink.io/docs/api/getting-started/overview)

[Data fields](https://microlink.io/docs/api/getting-started/data-fields)

[CLI](https://microlink.io/docs/api/getting-started/cli)

Basics

[Authentication](https://microlink.io/docs/api/basics/authentication)

[Cache](https://microlink.io/docs/api/basics/cache)

[Compression](https://microlink.io/docs/api/basics/compression)

[Endpoint](https://microlink.io/docs/api/basics/endpoint)

[Error codes](https://microlink.io/docs/api/basics/error-codes)

[Format](https://microlink.io/docs/api/basics/format)

[Rate limit](https://microlink.io/docs/api/basics/rate-limit)

Query Parameters

[adblock](https://microlink.io/docs/api/parameters/adblock)

[animations](https://microlink.io/docs/api/parameters/animations)

[audio](https://microlink.io/docs/api/parameters/audio)

[cacheKey](https://microlink.io/docs/api/parameters/cacheKey)

[click](https://microlink.io/docs/api/parameters/click)

[colorScheme](https://microlink.io/docs/api/parameters/colorScheme)

[data](https://microlink.io/docs/api/parameters/data)

[device](https://microlink.io/docs/api/parameters/device)

[embed](https://microlink.io/docs/api/parameters/embed)

[filename](https://microlink.io/docs/api/parameters/filename)

[filter](https://microlink.io/docs/api/parameters/filter)

[force](https://microlink.io/docs/api/parameters/force)

[function](https://microlink.io/docs/api/parameters/function)

[headers](https://microlink.io/docs/api/parameters/headers)

[iframe](https://microlink.io/docs/api/parameters/iframe)

[insights](https://microlink.io/docs/api/parameters/insights)

[lighthouse](https://microlink.io/docs/api/parameters/insights/lighthouse)

[technologies](https://microlink.io/docs/api/parameters/insights/technologies)

[javascript](https://microlink.io/docs/api/parameters/javascript)

[mediaType](https://microlink.io/docs/api/parameters/mediaType)

[meta](https://microlink.io/docs/api/parameters/meta)

[modules](https://microlink.io/docs/api/parameters/modules)

[palette](https://microlink.io/docs/api/parameters/palette)

[pdf](https://microlink.io/docs/api/parameters/pdf)

[format](https://microlink.io/docs/api/parameters/pdf/format)

[height](https://microlink.io/docs/api/parameters/pdf/height)

[landscape](https://microlink.io/docs/api/parameters/pdf/landscape)

[margin](https://microlink.io/docs/api/parameters/pdf/margin)

[pageRanges](https://microlink.io/docs/api/parameters/pdf/pageRanges)

[scale](https://microlink.io/docs/api/parameters/pdf/scale)

[width](https://microlink.io/docs/api/parameters/pdf/width)

[ping](https://microlink.io/docs/api/parameters/ping)

[prerender](https://microlink.io/docs/api/parameters/prerender)

[proxy](https://microlink.io/docs/api/parameters/proxy)

[retry](https://microlink.io/docs/api/parameters/retry)

[screenshot](https://microlink.io/docs/api/parameters/screenshot)

[codeScheme](https://microlink.io/docs/api/parameters/screenshot/codeScheme)

[element](https://microlink.io/docs/api/parameters/screenshot/element)

[fullPage](https://microlink.io/docs/api/parameters/screenshot/fullPage)

[overlay](https://microlink.io/docs/api/parameters/screenshot/overlay)

[omitBackground](https://microlink.io/docs/api/parameters/screenshot/omitBackground)

[type](https://microlink.io/docs/api/parameters/screenshot/type)

[scripts](https://microlink.io/docs/api/parameters/scripts)

[scroll](https://microlink.io/docs/api/parameters/scroll)

[styles](https://microlink.io/docs/api/parameters/styles)

[staleTtl](https://microlink.io/docs/api/parameters/staleTtl)

[timeout](https://microlink.io/docs/api/parameters/timeout)

[ttl](https://microlink.io/docs/api/parameters/ttl)

[url](https://microlink.io/docs/api/parameters/url)

[video](https://microlink.io/docs/api/parameters/video)

[viewport](https://microlink.io/docs/api/parameters/viewport)

[waitForSelector](https://microlink.io/docs/api/parameters/waitForSelector)

[waitForTimeout](https://microlink.io/docs/api/parameters/waitForTimeout)

[waitUntil](https://microlink.io/docs/api/parameters/waitUntil)

API GUIDES MQL SDK CARDS

Getting Started

[Overview](https://microlink.io/docs/api/getting-started/overview)

[Data fields](https://microlink.io/docs/api/getting-started/data-fields)

[CLI](https://microlink.io/docs/api/getting-started/cli)

Basics

[Authentication](https://microlink.io/docs/api/basics/authentication)

[Cache](https://microlink.io/docs/api/basics/cache)

[Compression](https://microlink.io/docs/api/basics/compression)

[Endpoint](https://microlink.io/docs/api/basics/endpoint)

[Error codes](https://microlink.io/docs/api/basics/error-codes)

[Format](https://microlink.io/docs/api/basics/format)

[Rate limit](https://microlink.io/docs/api/basics/rate-limit)

Query Parameters

[adblock](https://microlink.io/docs/api/parameters/adblock)

[animations](https://microlink.io/docs/api/parameters/animations)

[audio](https://microlink.io/docs/api/parameters/audio)

[cacheKey](https://microlink.io/docs/api/parameters/cacheKey)

[click](https://microlink.io/docs/api/parameters/click)

[colorScheme](https://microlink.io/docs/api/parameters/colorScheme)

[data](https://microlink.io/docs/api/parameters/data)

[device](https://microlink.io/docs/api/parameters/device)

[embed](https://microlink.io/docs/api/parameters/embed)

[filename](https://microlink.io/docs/api/parameters/filename)

[filter](https://microlink.io/docs/api/parameters/filter)

[force](https://microlink.io/docs/api/parameters/force)

[function](https://microlink.io/docs/api/parameters/function)

[headers](https://microlink.io/docs/api/parameters/headers)

[iframe](https://microlink.io/docs/api/parameters/iframe)

[insights](https://microlink.io/docs/api/parameters/insights)

[lighthouse](https://microlink.io/docs/api/parameters/insights/lighthouse)

[technologies](https://microlink.io/docs/api/parameters/insights/technologies)

[javascript](https://microlink.io/docs/api/parameters/javascript)

[mediaType](https://microlink.io/docs/api/parameters/mediaType)

[meta](https://microlink.io/docs/api/parameters/meta)

[modules](https://microlink.io/docs/api/parameters/modules)

[palette](https://microlink.io/docs/api/parameters/palette)

[pdf](https://microlink.io/docs/api/parameters/pdf)

[format](https://microlink.io/docs/api/parameters/pdf/format)

[height](https://microlink.io/docs/api/parameters/pdf/height)

[landscape](https://microlink.io/docs/api/parameters/pdf/landscape)

[margin](https://microlink.io/docs/api/parameters/pdf/margin)

[pageRanges](https://microlink.io/docs/api/parameters/pdf/pageRanges)

[scale](https://microlink.io/docs/api/parameters/pdf/scale)

[width](https://microlink.io/docs/api/parameters/pdf/width)

[ping](https://microlink.io/docs/api/parameters/ping)

[prerender](https://microlink.io/docs/api/parameters/prerender)

[proxy](https://microlink.io/docs/api/parameters/proxy)

[retry](https://microlink.io/docs/api/parameters/retry)

[screenshot](https://microlink.io/docs/api/parameters/screenshot)

[codeScheme](https://microlink.io/docs/api/parameters/screenshot/codeScheme)

[element](https://microlink.io/docs/api/parameters/screenshot/element)

[fullPage](https://microlink.io/docs/api/parameters/screenshot/fullPage)

[overlay](https://microlink.io/docs/api/parameters/screenshot/overlay)

[omitBackground](https://microlink.io/docs/api/parameters/screenshot/omitBackground)

[type](https://microlink.io/docs/api/parameters/screenshot/type)

[scripts](https://microlink.io/docs/api/parameters/scripts)

[scroll](https://microlink.io/docs/api/parameters/scroll)

[styles](https://microlink.io/docs/api/parameters/styles)

[staleTtl](https://microlink.io/docs/api/parameters/staleTtl)

[timeout](https://microlink.io/docs/api/parameters/timeout)

[ttl](https://microlink.io/docs/api/parameters/ttl)

[url](https://microlink.io/docs/api/parameters/url)

[video](https://microlink.io/docs/api/parameters/video)

[viewport](https://microlink.io/docs/api/parameters/viewport)

[waitForSelector](https://microlink.io/docs/api/parameters/waitForSelector)

[waitForTimeout](https://microlink.io/docs/api/parameters/waitForTimeout)

[waitUntil](https://microlink.io/docs/api/parameters/waitUntil)

## function

[Copy for LLM](https://microlink.io/docs/api/parameters/function.md "Copy content for LLM")

\|

[View as Markdown](https://microlink.io/docs/api/parameters/function.md "View content as Markdown")

Type: \<string\>

It runs JavaScript code with runtime access to a headless browser.

The following examples show how to use the Microlink API with CLI, cURL, JavaScript, Python, Ruby, PHP & Golang, targeting 'https://microlink.io' URL with 'function' & 'scripts' API parameters:

### CLI Microlink API example

```bash
microlink https://microlink.io&function='({ page }) => page.evaluate("jQuery.fn.jquery")'&scripts=https://code.jquery.com/jquery-3.5.0.min.js
```

### cURL Microlink API example

```bash
curl -G "https://api.microlink.io" \
  -d "url=https://microlink.io" \
  -d "function=(%7B%20page%20%7D)%20%3D%3E%20page.evaluate(%22jQuery.fn.jquery%22)" \
  -d "scripts=https://code.jquery.com/jquery-3.5.0.min.js"
```

### JavaScript Microlink API example

```javascript
import mql from '@microlink/mql'

const { data } = await mql('https://microlink.io', {
  function: '({ page }) => page.evaluate("jQuery.fn.jquery")',
  scripts: [
    "https://code.jquery.com/jquery-3.5.0.min.js"
  ]
})
```

### Python Microlink API example

```python
import requests

url = "https://api.microlink.io/"

querystring = {
    "url": "https://microlink.io",
    "function": '''({ page }) => page.evaluate("jQuery.fn.jquery")''',
    "scripts": "https://code.jquery.com/jquery-3.5.0.min.js"
}

response = requests.get(url, params=querystring)

print(response.json())
```

### Ruby Microlink API example

```ruby
require 'uri'
require 'net/http'

base_url = "https://api.microlink.io/"

params = {
  url: "https://microlink.io",
  function: '({ page }) => page.evaluate("jQuery.fn.jquery")',
  scripts: "https://code.jquery.com/jquery-3.5.0.min.js"
}

uri = URI(base_url)
uri.query = URI.encode_www_form(params)

http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = true

request = Net::HTTP::Get.new(uri)
response = http.request(request)

puts response.body
```

### PHP Microlink API example

```php
<?php

$baseUrl = "https://api.microlink.io/";

$params = [
    "url" => "https://microlink.io",
    "function" => '({ page }) => page.evaluate("jQuery.fn.jquery")',
    "scripts" => "https://code.jquery.com/jquery-3.5.0.min.js"
];

$query = http_build_query($params);
$url = $baseUrl . '?' . $query;

$curl = curl_init();

curl_setopt_array($curl, [
    CURLOPT_URL => $url,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_ENCODING => "",
    CURLOPT_MAXREDIRS => 10,
    CURLOPT_TIMEOUT => 30,
    CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
    CURLOPT_CUSTOMREQUEST => "GET"
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
    echo "cURL Error #: " . $err;
} else {
    echo $response;
}
```

### Golang Microlink API example

```
package main

import (
    "fmt"
    "net/http"
    "net/url"
    "io"
)

func main() {
    baseURL := "https://api.microlink.io"

    u, err := url.Parse(baseURL)
    if err != nil {
        panic(err)
    }
    fn := `({ page }) => page.evaluate("jQuery.fn.jquery")`

    q := u.Query()
    q.Set("url", "https://microlink.io")
    q.Set("function", fn)
    q.Set("scripts", "https://code.jquery.com/jquery-3.5.0.min.js")
    u.RawQuery = q.Encode()

    req, err := http.NewRequest("GET", u.String(), nil)
    if err != nil {
        panic(err)
    }

    client := &http.Client{}
    resp, err := client.Do(req)
    if err != nil {
        panic(err)
    }
    defer resp.Body.Close()

    body, err := io.ReadAll(resp.Body)
    if err != nil {
        panic(err)
    }

    fmt.Println(string(body))
}
```

```javascript
import mql from '@microlink/mql'

const { data } = await mql('https://microlink.io', {

  function: '({ page }) => page.evaluate("jQuery.fn.jquery")',

  scripts: [

    "https://code.jquery.com/jquery-3.5.0.min.js"

  ]

})
```

The function will receive any extra query parameter provided, plus:

### Page

The full [puppeteer#page](https://pptr.dev/api/puppeteer.page) object. When the function references `page`, Microlink navigates to the URL in a browser before calling your function. Any Puppeteer page method is available:

The following examples show how to use the Microlink API with CLI, cURL, JavaScript, Python, Ruby, PHP & Golang, targeting 'https://example.com' URL with 'function' & 'meta' API parameters:

### CLI Microlink API example

```bash
microlink https://example.com&function='({ page }) => page.title()'
```

### cURL Microlink API example

```bash
curl -G "https://api.microlink.io" \
  -d "url=https://example.com" \
  -d "function=(%7B%20page%20%7D)%20%3D%3E%20page.title()" \
  -d "meta=false"
```

### JavaScript Microlink API example

```javascript
import mql from '@microlink/mql'

const { data } = await mql('https://example.com', {
  function: "({ page }) => page.title()",
  meta: false
})
```

### Python Microlink API example

```python
import requests

url = "https://api.microlink.io/"

querystring = {
    "url": "https://example.com",
    "function": "({ page }) => page.title()",
    "meta": "false"
}

response = requests.get(url, params=querystring)

print(response.json())
```

### Ruby Microlink API example

```ruby
require 'uri'
require 'net/http'

base_url = "https://api.microlink.io/"

params = {
  url: "https://example.com",
  function: "({ page }) => page.title()",
  meta: "false"
}

uri = URI(base_url)
uri.query = URI.encode_www_form(params)

http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = true

request = Net::HTTP::Get.new(uri)
response = http.request(request)

puts response.body
```

### PHP Microlink API example

```php
<?php

$baseUrl = "https://api.microlink.io/";

$params = [
    "url" => "https://example.com",
    "function" => "({ page }) => page.title()",
    "meta" => "false"
];

$query = http_build_query($params);
$url = $baseUrl . '?' . $query;

$curl = curl_init();

curl_setopt_array($curl, [
    CURLOPT_URL => $url,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_ENCODING => "",
    CURLOPT_MAXREDIRS => 10,
    CURLOPT_TIMEOUT => 30,
    CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
    CURLOPT_CUSTOMREQUEST => "GET"
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
    echo "cURL Error #: " . $err;
} else {
    echo $response;
}
```

### Golang Microlink API example

```
package main

import (
    "fmt"
    "net/http"
    "net/url"
    "io"
)

func main() {
    baseURL := "https://api.microlink.io"

    u, err := url.Parse(baseURL)
    if err != nil {
        panic(err)
    }
    q := u.Query()
    q.Set("url", "https://example.com")
    q.Set("function", "({ page }) => page.title()")
    q.Set("meta", "false")
    u.RawQuery = q.Encode()

    req, err := http.NewRequest("GET", u.String(), nil)
    if err != nil {
        panic(err)
    }

    client := &http.Client{}
    resp, err := client.Do(req)
    if err != nil {
        panic(err)
    }
    defer resp.Body.Close()

    body, err := io.ReadAll(resp.Body)
    if err != nil {
        panic(err)
    }

    fmt.Println(string(body))
}
```

```javascript
import mql from '@microlink/mql'

const { data } = await mql('https://example.com', {

  function: "({ page }) => page.title()",

  meta: false

})
```

Get the document title.

The following examples show how to use the Microlink API with CLI, cURL, JavaScript, Python, Ruby, PHP & Golang, targeting 'https://example.com' URL with 'function' & 'meta' API parameters:

### CLI Microlink API example

```bash
microlink https://example.com&function='({ page }) => page.$eval('"'"'h1'"'"', el => el.textContent)'
```

### cURL Microlink API example

```bash
curl -G "https://api.microlink.io" \
  -d "url=https://example.com" \
  -d "function=(%7B%20page%20%7D)%20%3D%3E%20page.%24eval('h1'%2C%20el%20%3D%3E%20el.textContent)" \
  -d "meta=false"
```

### JavaScript Microlink API example

```javascript
import mql from '@microlink/mql'

const { data } = await mql('https://example.com', {
  function: "({ page }) => page.$eval('h1', el => el.textContent)",
  meta: false
})
```

### Python Microlink API example

```python
import requests

url = "https://api.microlink.io/"

querystring = {
    "url": "https://example.com",
    "function": '''({ page }) => page.$eval('h1', el => el.textContent)''',
    "meta": "false"
}

response = requests.get(url, params=querystring)

print(response.json())
```

### Ruby Microlink API example

```ruby
require 'uri'
require 'net/http'

base_url = "https://api.microlink.io/"

params = {
  url: "https://example.com",
  function: "({ page }) => page.$eval('h1', el => el.textContent)",
  meta: "false"
}

uri = URI(base_url)
uri.query = URI.encode_www_form(params)

http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = true

request = Net::HTTP::Get.new(uri)
response = http.request(request)

puts response.body
```

### PHP Microlink API example

```php
<?php

$baseUrl = "https://api.microlink.io/";

$params = [
    "url" => "https://example.com",
    "function" => "({ page }) => page.$eval('h1', el => el.textContent)",
    "meta" => "false"
];

$query = http_build_query($params);
$url = $baseUrl . '?' . $query;

$curl = curl_init();

curl_setopt_array($curl, [
    CURLOPT_URL => $url,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_ENCODING => "",
    CURLOPT_MAXREDIRS => 10,
    CURLOPT_TIMEOUT => 30,
    CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
    CURLOPT_CUSTOMREQUEST => "GET"
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
    echo "cURL Error #: " . $err;
} else {
    echo $response;
}
```

### Golang Microlink API example

```
package main

import (
    "fmt"
    "net/http"
    "net/url"
    "io"
)

func main() {
    baseURL := "https://api.microlink.io"

    u, err := url.Parse(baseURL)
    if err != nil {
        panic(err)
    }
    fn := `({ page }) => page.$eval('h1', el => el.textContent)`

    q := u.Query()
    q.Set("url", "https://example.com")
    q.Set("function", fn)
    q.Set("meta", "false")
    u.RawQuery = q.Encode()

    req, err := http.NewRequest("GET", u.String(), nil)
    if err != nil {
        panic(err)
    }

    client := &http.Client{}
    resp, err := client.Do(req)
    if err != nil {
        panic(err)
    }
    defer resp.Body.Close()

    body, err := io.ReadAll(resp.Body)
    if err != nil {
        panic(err)
    }

    fmt.Println(string(body))
}
```

```javascript
import mql from '@microlink/mql'

const { data } = await mql('https://example.com', {

  function: "({ page }) => page.$eval('h1', el => el.textContent)",

  meta: false

})
```

Extract text from a DOM element.

The following examples show how to use the Microlink API with CLI, cURL, JavaScript, Python, Ruby, PHP & Golang, targeting 'https://example.com' URL with 'function' & 'meta' API parameters:

### CLI Microlink API example

```bash
microlink https://example.com&function='({ page }) => page.$$eval('"'"'a'"'"', links => links.map(a => a.href))'
```

### cURL Microlink API example

```bash
curl -G "https://api.microlink.io" \
  -d "url=https://example.com" \
  -d "function=(%7B%20page%20%7D)%20%3D%3E%20page.%24%24eval('a'%2C%20links%20%3D%3E%20links.map(a%20%3D%3E%20a.href))" \
  -d "meta=false"
```

### JavaScript Microlink API example

```javascript
import mql from '@microlink/mql'

const { data } = await mql('https://example.com', {
  function: "({ page }) => page.$$eval('a', links => links.map(a => a.href))",
  meta: false
})
```

### Python Microlink API example

```python
import requests

url = "https://api.microlink.io/"

querystring = {
    "url": "https://example.com",
    "function": '''({ page }) => page.$$eval('a', links => links.map(a => a.href))''',
    "meta": "false"
}

response = requests.get(url, params=querystring)

print(response.json())
```

### Ruby Microlink API example

```ruby
require 'uri'
require 'net/http'

base_url = "https://api.microlink.io/"

params = {
  url: "https://example.com",
  function: "({ page }) => page.$$eval('a', links => links.map(a => a.href))",
  meta: "false"
}

uri = URI(base_url)
uri.query = URI.encode_www_form(params)

http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = true

request = Net::HTTP::Get.new(uri)
response = http.request(request)

puts response.body
```

### PHP Microlink API example

```php
<?php

$baseUrl = "https://api.microlink.io/";

$params = [
    "url" => "https://example.com",
    "function" => "({ page }) => page.$$eval('a', links => links.map(a => a.href))",
    "meta" => "false"
];

$query = http_build_query($params);
$url = $baseUrl . '?' . $query;

$curl = curl_init();

curl_setopt_array($curl, [
    CURLOPT_URL => $url,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_ENCODING => "",
    CURLOPT_MAXREDIRS => 10,
    CURLOPT_TIMEOUT => 30,
    CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
    CURLOPT_CUSTOMREQUEST => "GET"
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
    echo "cURL Error #: " . $err;
} else {
    echo $response;
}
```

### Golang Microlink API example

```
package main

import (
    "fmt"
    "net/http"
    "net/url"
    "io"
)

func main() {
    baseURL := "https://api.microlink.io"

    u, err := url.Parse(baseURL)
    if err != nil {
        panic(err)
    }
    fn := `({ page }) => page.$$eval('a', links => links.map(a => a.href))`

    q := u.Query()
    q.Set("url", "https://example.com")
    q.Set("function", fn)
    q.Set("meta", "false")
    u.RawQuery = q.Encode()

    req, err := http.NewRequest("GET", u.String(), nil)
    if err != nil {
        panic(err)
    }

    client := &http.Client{}
    resp, err := client.Do(req)
    if err != nil {
        panic(err)
    }
    defer resp.Body.Close()

    body, err := io.ReadAll(resp.Body)
    if err != nil {
        panic(err)
    }

    fmt.Println(string(body))
}
```

```javascript
import mql from '@microlink/mql'

const { data } = await mql('https://example.com', {

  function: "({ page }) => page.$$eval('a', links => links.map(a => a.href))",

  meta: false

})
```

Collect all links on the page.

The following examples show how to use the Microlink API with CLI, cURL, JavaScript, Python, Ruby, PHP & Golang, targeting 'https://example.com' URL with 'function' & 'meta' API parameters:

### CLI Microlink API example

```bash
microlink https://example.com&function='({ page }) => page.evaluate(() => ({
  viewport: { width: window.innerWidth, height: window.innerHeight },
  cookies: document.cookie.length,
  resources: performance.getEntriesByType('"'"'resource'"'"').length
}))'
```

### cURL Microlink API example

```bash
curl -G "https://api.microlink.io" \
  -d "url=https://example.com" \
  -d "function=(%7B%20page%20%7D)%20%3D%3E%20page.evaluate(()%20%3D%3E%20(%7B%0A%20%20viewport%3A%20%7B%20width%3A%20window.innerWidth%2C%20height%3A%20window.innerHeight%20%7D%2C%0A%20%20cookies%3A%20document.cookie.length%2C%0A%20%20resources%3A%20performance.getEntriesByType('resource').length%0A%7D))" \
  -d "meta=false"
```

### JavaScript Microlink API example

```javascript
import mql from '@microlink/mql'

const { data } = await mql('https://example.com', {
  function: "({ page }) => page.evaluate(() => ({
  viewport: { width: window.innerWidth, height: window.innerHeight },
  cookies: document.cookie.length,
  resources: performance.getEntriesByType('resource').length
}))",
  meta: false
})
```

### Python Microlink API example

```python
import requests

url = "https://api.microlink.io/"

querystring = {
    "url": "https://example.com",
    "function": '''({ page }) => page.evaluate(() => ({
  viewport: { width: window.innerWidth, height: window.innerHeight },
  cookies: document.cookie.length,
  resources: performance.getEntriesByType('resource').length
}))''',
    "meta": "false"
}

response = requests.get(url, params=querystring)

print(response.json())
```

### Ruby Microlink API example

```ruby
require 'uri'
require 'net/http'

base_url = "https://api.microlink.io/"

params = {
  url: "https://example.com",
  function: "({ page }) => page.evaluate(() => ({
  viewport: { width: window.innerWidth, height: window.innerHeight },
  cookies: document.cookie.length,
  resources: performance.getEntriesByType('resource').length
}))",
  meta: "false"
}

uri = URI(base_url)
uri.query = URI.encode_www_form(params)

http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = true

request = Net::HTTP::Get.new(uri)
response = http.request(request)

puts response.body
```

### PHP Microlink API example

```php
<?php

$baseUrl = "https://api.microlink.io/";

$params = [
    "url" => "https://example.com",
    "function" => "({ page }) => page.evaluate(() => ({
  viewport: { width: window.innerWidth, height: window.innerHeight },
  cookies: document.cookie.length,
  resources: performance.getEntriesByType('resource').length
}))",
    "meta" => "false"
];

$query = http_build_query($params);
$url = $baseUrl . '?' . $query;

$curl = curl_init();

curl_setopt_array($curl, [
    CURLOPT_URL => $url,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_ENCODING => "",
    CURLOPT_MAXREDIRS => 10,
    CURLOPT_TIMEOUT => 30,
    CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
    CURLOPT_CUSTOMREQUEST => "GET"
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
    echo "cURL Error #: " . $err;
} else {
    echo $response;
}
```

### Golang Microlink API example

```
package main

import (
    "fmt"
    "net/http"
    "net/url"
    "io"
)

func main() {
    baseURL := "https://api.microlink.io"

    u, err := url.Parse(baseURL)
    if err != nil {
        panic(err)
    }
    fn := `({ page }) => page.evaluate(() => ({
  viewport: { width: window.innerWidth, height: window.innerHeight },
  cookies: document.cookie.length,
  resources: performance.getEntriesByType('resource').length
}))`

    q := u.Query()
    q.Set("url", "https://example.com")
    q.Set("function", fn)
    q.Set("meta", "false")
    u.RawQuery = q.Encode()

    req, err := http.NewRequest("GET", u.String(), nil)
    if err != nil {
        panic(err)
    }

    client := &http.Client{}
    resp, err := client.Do(req)
    if err != nil {
        panic(err)
    }
    defer resp.Body.Close()

    body, err := io.ReadAll(resp.Body)
    if err != nil {
        panic(err)
    }

    fmt.Println(string(body))
}
```

```javascript
import mql from '@microlink/mql'

const { data } = await mql('https://example.com', {

  function: "({ page }) => page.evaluate(() => ({

  viewport: { width: window.innerWidth, height: window.innerHeight },

  cookies: document.cookie.length,

  resources: performance.getEntriesByType('resource').length

}))",

  meta: false

})
```

Run arbitrary JavaScript in the browser page context via `page.evaluate`.

### Response

The [puppeteer#response](https://pptr.dev/api/puppeteer.httpresponse) as result of the implicit [page.goto](https://pptr.dev/api/puppeteer.page.goto). Only available when the function uses `page`:

The following examples show how to use the Microlink API with CLI, cURL, JavaScript, Python, Ruby, PHP & Golang, targeting 'https://edge-ping.vercel.app' URL with 'function' & 'meta' API parameters:

### CLI Microlink API example

```bash
microlink https://edge-ping.vercel.app&function='({ page, response }) => response.status()'
```

### cURL Microlink API example

```bash
curl -G "https://api.microlink.io" \
  -d "url=https://edge-ping.vercel.app" \
  -d "function=(%7B%20page%2C%20response%20%7D)%20%3D%3E%20response.status()" \
  -d "meta=false"
```

### JavaScript Microlink API example

```javascript
import mql from '@microlink/mql'

const { data } = await mql('https://edge-ping.vercel.app', {
  function: "({ page, response }) => response.status()",
  meta: false
})
```

### Python Microlink API example

```python
import requests

url = "https://api.microlink.io/"

querystring = {
    "url": "https://edge-ping.vercel.app",
    "function": "({ page, response }) => response.status()",
    "meta": "false"
}

response = requests.get(url, params=querystring)

print(response.json())
```

### Ruby Microlink API example

```ruby
require 'uri'
require 'net/http'

base_url = "https://api.microlink.io/"

params = {
  url: "https://edge-ping.vercel.app",
  function: "({ page, response }) => response.status()",
  meta: "false"
}

uri = URI(base_url)
uri.query = URI.encode_www_form(params)

http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = true

request = Net::HTTP::Get.new(uri)
response = http.request(request)

puts response.body
```

### PHP Microlink API example

```php
<?php

$baseUrl = "https://api.microlink.io/";

$params = [
    "url" => "https://edge-ping.vercel.app",
    "function" => "({ page, response }) => response.status()",
    "meta" => "false"
];

$query = http_build_query($params);
$url = $baseUrl . '?' . $query;

$curl = curl_init();

curl_setopt_array($curl, [
    CURLOPT_URL => $url,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_ENCODING => "",
    CURLOPT_MAXREDIRS => 10,
    CURLOPT_TIMEOUT => 30,
    CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
    CURLOPT_CUSTOMREQUEST => "GET"
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
    echo "cURL Error #: " . $err;
} else {
    echo $response;
}
```

### Golang Microlink API example

```
package main

import (
    "fmt"
    "net/http"
    "net/url"
    "io"
)

func main() {
    baseURL := "https://api.microlink.io"

    u, err := url.Parse(baseURL)
    if err != nil {
        panic(err)
    }
    q := u.Query()
    q.Set("url", "https://edge-ping.vercel.app")
    q.Set("function", "({ page, response }) => response.status()")
    q.Set("meta", "false")
    u.RawQuery = q.Encode()

    req, err := http.NewRequest("GET", u.String(), nil)
    if err != nil {
        panic(err)
    }

    client := &http.Client{}
    resp, err := client.Do(req)
    if err != nil {
        panic(err)
    }
    defer resp.Body.Close()

    body, err := io.ReadAll(resp.Body)
    if err != nil {
        panic(err)
    }

    fmt.Println(string(body))
}
```

```javascript
import mql from '@microlink/mql'

const { data } = await mql('https://edge-ping.vercel.app', {

  function: "({ page, response }) => response.status()",

  meta: false

})
```

### Headers

The request headers used to fetch the target URL:

The following examples show how to use the Microlink API with CLI, cURL, JavaScript, Python, Ruby, PHP & Golang, targeting 'https://example.com' URL with 'function' & 'meta' API parameters:

### CLI Microlink API example

```bash
microlink https://example.com&function='({ headers }) => headers["user-agent"]'
```

### cURL Microlink API example

```bash
curl -G "https://api.microlink.io" \
  -d "url=https://example.com" \
  -d "function=(%7B%20headers%20%7D)%20%3D%3E%20headers%5B%22user-agent%22%5D" \
  -d "meta=false"
```

### JavaScript Microlink API example

```javascript
import mql from '@microlink/mql'

const { data } = await mql('https://example.com', {
  function: '({ headers }) => headers["user-agent"]',
  meta: false
})
```

### Python Microlink API example

```python
import requests

url = "https://api.microlink.io/"

querystring = {
    "url": "https://example.com",
    "function": '''({ headers }) => headers["user-agent"]''',
    "meta": "false"
}

response = requests.get(url, params=querystring)

print(response.json())
```

### Ruby Microlink API example

```ruby
require 'uri'
require 'net/http'

base_url = "https://api.microlink.io/"

params = {
  url: "https://example.com",
  function: '({ headers }) => headers["user-agent"]',
  meta: "false"
}

uri = URI(base_url)
uri.query = URI.encode_www_form(params)

http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = true

request = Net::HTTP::Get.new(uri)
response = http.request(request)

puts response.body
```

### PHP Microlink API example

```php
<?php

$baseUrl = "https://api.microlink.io/";

$params = [
    "url" => "https://example.com",
    "function" => '({ headers }) => headers["user-agent"]',
    "meta" => "false"
];

$query = http_build_query($params);
$url = $baseUrl . '?' . $query;

$curl = curl_init();

curl_setopt_array($curl, [
    CURLOPT_URL => $url,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_ENCODING => "",
    CURLOPT_MAXREDIRS => 10,
    CURLOPT_TIMEOUT => 30,
    CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
    CURLOPT_CUSTOMREQUEST => "GET"
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
    echo "cURL Error #: " . $err;
} else {
    echo $response;
}
```

### Golang Microlink API example

```
package main

import (
    "fmt"
    "net/http"
    "net/url"
    "io"
)

func main() {
    baseURL := "https://api.microlink.io"

    u, err := url.Parse(baseURL)
    if err != nil {
        panic(err)
    }
    fn := `({ headers }) => headers["user-agent"]`

    q := u.Query()
    q.Set("url", "https://example.com")
    q.Set("function", fn)
    q.Set("meta", "false")
    u.RawQuery = q.Encode()

    req, err := http.NewRequest("GET", u.String(), nil)
    if err != nil {
        panic(err)
    }

    client := &http.Client{}
    resp, err := client.Do(req)
    if err != nil {
        panic(err)
    }
    defer resp.Body.Close()

    body, err := io.ReadAll(resp.Body)
    if err != nil {
        panic(err)
    }

    fmt.Println(string(body))
}
```

```javascript
import mql from '@microlink/mql'

const { data } = await mql('https://example.com', {

  function: '({ headers }) => headers["user-agent"]',

  meta: false

})
```

### Custom parameters

Any extra query parameter is forwarded to the function:

The following examples show how to use the Microlink API with CLI, cURL, JavaScript, Python, Ruby, PHP & Golang, targeting 'https://example.com' URL with 'function', 'greetings' & 'meta' API parameters:

### CLI Microlink API example

```bash
microlink https://example.com&function='({ greetings }) => greetings'&greetings='hello world'
```

### cURL Microlink API example

```bash
curl -G "https://api.microlink.io" \
  -d "url=https://example.com" \
  -d "function=(%7B%20greetings%20%7D)%20%3D%3E%20greetings" \
  -d "greetings=hello%20world" \
  -d "meta=false"
```

### JavaScript Microlink API example

```javascript
import mql from '@microlink/mql'

const { data } = await mql('https://example.com', {
  function: "({ greetings }) => greetings",
  greetings: "hello world",
  meta: false
})
```

### Python Microlink API example

```python
import requests

url = "https://api.microlink.io/"

querystring = {
    "url": "https://example.com",
    "function": "({ greetings }) => greetings",
    "greetings": "hello world",
    "meta": "false"
}

response = requests.get(url, params=querystring)

print(response.json())
```

### Ruby Microlink API example

```ruby
require 'uri'
require 'net/http'

base_url = "https://api.microlink.io/"

params = {
  url: "https://example.com",
  function: "({ greetings }) => greetings",
  greetings: "hello world",
  meta: "false"
}

uri = URI(base_url)
uri.query = URI.encode_www_form(params)

http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = true

request = Net::HTTP::Get.new(uri)
response = http.request(request)

puts response.body
```

### PHP Microlink API example

```php
<?php

$baseUrl = "https://api.microlink.io/";

$params = [
    "url" => "https://example.com",
    "function" => "({ greetings }) => greetings",
    "greetings" => "hello world",
    "meta" => "false"
];

$query = http_build_query($params);
$url = $baseUrl . '?' . $query;

$curl = curl_init();

curl_setopt_array($curl, [
    CURLOPT_URL => $url,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_ENCODING => "",
    CURLOPT_MAXREDIRS => 10,
    CURLOPT_TIMEOUT => 30,
    CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
    CURLOPT_CUSTOMREQUEST => "GET"
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
    echo "cURL Error #: " . $err;
} else {
    echo $response;
}
```

### Golang Microlink API example

```
package main

import (
    "fmt"
    "net/http"
    "net/url"
    "io"
)

func main() {
    baseURL := "https://api.microlink.io"

    u, err := url.Parse(baseURL)
    if err != nil {
        panic(err)
    }
    q := u.Query()
    q.Set("url", "https://example.com")
    q.Set("function", "({ greetings }) => greetings")
    q.Set("greetings", "hello world")
    q.Set("meta", "false")
    u.RawQuery = q.Encode()

    req, err := http.NewRequest("GET", u.String(), nil)
    if err != nil {
        panic(err)
    }

    client := &http.Client{}
    resp, err := client.Do(req)
    if err != nil {
        panic(err)
    }
    defer resp.Body.Close()

    body, err := io.ReadAll(resp.Body)
    if err != nil {
        panic(err)
    }

    fmt.Println(string(body))
}
```

```javascript
import mql from '@microlink/mql'

const { data } = await mql('https://example.com', {

  function: "({ greetings }) => greetings",

  greetings: "hello world",

  meta: false

})
```

## Response

The result is wrapped under `data.function`:

```json
{

  "status": "success",

  "data": {

    "function": {

      "isFulfilled": true,

      "value": "3.5.0",

      "profiling": {

        "phases": {

          "install": 0,

          "build": 120,

          "spawn": 45,

          "run": 890,

          "total": 1055

        },

        "cpu": 234,

        "memory": 8,

        "size": 156

      },

      "logging": {}

    }

  }

}
```

| Field         | Description                                                                                     |
| ------------- | ----------------------------------------------------------------------------------------------- |
| `isFulfilled` | `true` when the function completed without errors                                               |
| `value`       | The return value on success, or `{ name, message }` on failure                                  |
| `profiling`   | Execution metrics: phase durations (ms), peak CPU time (ms), memory (MB), and code size (bytes) |
| `logging`     | Captured console output from the function runtime                                               |

The profiling phases are:

| Phase     | Description                                                  |
| --------- | ------------------------------------------------------------ |
| `install` | Time spent installing npm dependencies detected in your code |
| `build`   | Time spent bundling the function code                        |
| `spawn`   | Time spent starting the isolated runtime process             |
| `run`     | Time spent executing the function itself                     |
| `total`   | Wall-clock time from start to finish                         |

## Plan limits

The function parameter is available on both free and pro plans with different resource limits:

|             | Free       | Pro              |
| ----------- | ---------- | ---------------- |
| Timeout     | 5 seconds  | Up to 28 seconds |
| Memory      | 16 MB      | 32 MB            |
| Code size   | 1024 bytes | Unlimited        |
| Concurrency | 1 per IP   | Unlimited        |

When a limit is exceeded, the function returns `isFulfilled: false` with a descriptive error instead of failing the entire request:

```json
{

  "data": {

    "function": {

      "isFulfilled": false,

      "value": {

        "name": "TimeoutError",

        "message": "Function exceeded the 5s free plan timeout. Upgrade to pro for up to 28s."

      },

      "profiling": {},

      "logging": {}

    }

  }

}
```

The resource error types are:

| Error              | Trigger                                                              |
| ------------------ | -------------------------------------------------------------------- |
| `TimeoutError`     | Function wall-clock time exceeded the plan limit                     |
| `CpuTimeError`     | Function CPU time exceeded the plan limit                            |
| `MemoryError`      | Function memory usage exceeded the plan limit                        |
| `CodeSizeError`    | Function code exceeds the 1024 bytes free plan limit                 |
| `ConcurrencyError` | Too many concurrent function executions for the free plan (1 per IP) |

Each error message is plan-aware and tells you the exact limit that was hit.

## Compression

Since the function body can be large, you can compress it:

```js
const { compressToURI } = require('lz-ts')

const mql = require('@microlink/mql')

const code = ({ page }) => page.evaluate('jQuery.fn.jquery')

const { status, data } = await mql('https://microlink.io', {

  function: `lz#${compressToURI(code.toString())}`,

  meta: false,

  scripts: 'https://code.jquery.com/jquery-3.5.0.min.js'

})

mql.render(data.function)
```

Prefix the compressed data with the compressor alias.

The following compression algorithms are supported:

- brotli (`br`)
- gzip (`gz`)
- lz-string (`lz`)

If you use the

[@microlink/function](https://www.npmjs.com/package/@microlink/function)

library, compression is handled automatically.

Read [how to compress](https://microlink.io/blog/compress) to know more.

## NPM packages

The function runtime supports `require()` for any npm package. Dependencies are detected automatically from your code and installed on-the-fly during the install phase.

```js
const mql = require('@microlink/mql')

const code = () => {

  const cheerio = require('cheerio')

  const $ = cheerio.load('<h1>Hello world</h1>')

  return $('h1').text()

}

const { data } = await mql('https://example.com', {

  function: code.toString(),

  meta: false

})
```

Dependencies are parsed from your function code, installed in a sandbox, and cached for subsequent runs.

The runtime restricts certain system capabilities for security. Operations such as spawning child processes or writing to the filesystem outside the sandbox are not permitted.

## Function constructor

The most convenient way to use `function` is through the [@microlink/function](https://www.npmjs.com/package/@microlink/function) library:

```js
const microlink = require('@microlink/function')

const getTitle = microlink(({ page }) => page.title())

const result = await getTitle('https://example.com')

console.log(result.value) // 'Example Domain'
```

It lets you write normal JavaScript functions instead of managing string serialization and compression yourself:

See the [function guide](https://microlink.io/docs/guides/function) for practical examples covering page interaction, npm packages, error handling, and profiling.

Last updated on May 24, 2026

[Edit on GitHub](https://github.com/microlinkhq/www/blob/master/src/content/docs/api/parameters/function.md)